I swapped out the wireless usb NIC in question (DWA-140 DLINK) with another vendor. Choosing ETH0 as primary NIC during Ubuntu server install, WLAN0 works fine so I have to conclude that:

> if you install Ubuntu 12.04 server (32 bit) on a dell 755 with a DLINK DWA-140 B2 and select WLAN0 as your primary NIC then put in your WPA ESSID and pass phrase it connects to the net during install and patches itsels and works fine after many many many warm, cold, and tepid reboots with no problems.

However ...
> if you select ETH0 ... and that NIC does not route to the internet ... then your DLINK DWA-140 B2 will seem to work and the light will flash and yet it will not work at all ... for you are Damned ... and lost forever.

Issue resolved.
I win the smilly face :D

AH! But in your OP you didn't mention a usb wireless. That would have made all the dif. From what I've read those things can get really screwy at times and can require a ton of trouble shooting. If you can even get them to work at all.

One noob to another: The two biggest issues that *nix still has for new users is anything wireless and printers. And usb wireless is even more screwy than regular wireless; which has plenty of issues of its own.